Well researched but you must have missed the part where the PM said if you can’t go from Sydney to Perth then you can’t go from Singapore to Perth. Or if your state is not open to Australia then you won’t be getting any international students. I’m not sure how many international students go to uni in WA but the answer will be some and you can bet those University’s will be in the WA premiers ear. But I agree entirely that the premiers are driven by their approval ratings, not COVID rates.
edit - I do now, 2017 figures, 50,000 international students, $1.9 billion dollars.